In 2026, Japanese bullet trains (Shinkansen) can be extremely crowded, but "crowded" in Japan is very orderly. During peak commuting hours (7:30 AM – 9:00 AM) and "Golden Week" or "New Year" holidays, trains can reach 100% capacity, with standing-room-only in the Non-Reserved (Jiyu-seki) cars. However, unlike local subways, the Shinkansen system is designed for long-distance travel, so most passengers have a reserved seat. If you have a reservation, the train won't "feel" crowded once you are in your seat, as the cars are spacious and quiet. The most crowded routes are the Tokaido Shinkansen (Tokyo to Osaka) and the Sanyo Shinkansen (Osaka to Fukuoka). To avoid the crowds in 2026, travelers should always book a "Reserved Seat" (Shitei-seki) through the Smart EX app or at a ticket machine; it usually only costs about $5–$7 more than a non-reserved ticket and guarantees you a spot. If you are traveling with large luggage, remember that since 2020, you must reserve a "luggage space" seat in advance for any bag over a certain size, or you may be denied boarding or fined, which adds another layer of planning to avoid the mid-day rush.